5-Series (E12,E28, E34, E39, E60)Chat relating to the BMW 5-Series of all generations. Specific models include: BMW 518, BMW 520, BMW 520i, BMW 530i, BMW 528i, BMW 530i, BMW 518i, BMW 524d, BMW 525i, BMW 525e, BMW 528e, BMW 540i, BMW 535i, BMW 520d, BMW 525td, BMW 525d, BMW 530d, BMW 525i/xi, BMW 530i/xi. (BMW 5-Series Forum)
I have a 97 540i with 180K miles. Never had any serious problems until I started getting the classic "Smoke on Startup" problem. Did lots of research on the forums that led me to the OSV.
I originally replaced the OSV without removing the intake manifold, what a pain. When I inspected the orange diaphragm, it didn't have the rips that were common with others. After the replacement was done I would hear the diaphragm vibrating, holding my hand on the back of the manifold would quiet it.
Thinking I didn't do something right the next step was to remove the intake manifold. It was full of oil. While this was out I replaced the "cyclone valve" behind the timing chain cover, the various pipes and tubing under the manifold, intake gaskets and all the o-rings that were accessible. Put it all back together and it started and ran fine, for about 2 weeks. Then another Smoke on Startup.
So now thinking I may have installed a bad OSV I replaced just the rubber diaphragm (following instructions from another thread) by popping just the cap off.
Now I have a vibrating diaphragm again and still get the frequent smoke on startup.
Bought an inspection mirror (mirror on a stick) and noticed the OSV diaphragm cap was not fully snapped on all the tabs. Fully seated it and the vibration is now gone. A little bit of smoke still on startup but not enough run time to tell if this was the culprit.
Well done. I have recently done mine as well, it wasn't until I had put it all back together that I found a seperate piece that sits over the tube on the inside face. I ended up pulling it back off to check if it was from the original or the new unit, it was from the old, but I had to be sure. There will probably be a bit of oil left in the system which should dissipate over the course of a couple of drives.
I'm posting this in case someone else ends up with the same problem I did
After fully snapping the diaphram cover on, I continued to get the occasional smoke. I was checking hoses and connections for the umpteenth time and discovered the short-fat hose that connects to the back of the OSV's 90 degree elbow was loose. I was so loose I could spin it. After replacing both factory hose clamps I have been smoke free for over a month.
This vacuum leak may have been my problem all along as the original rubber diaphram was not torn and in decent shape.
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